The present invention relates to a device for the management of electrical sockets of a domestic or industrial type connected to an a.c. electrical network.
An electrical socket, as is known, constitutes the interface that enables transfer to a generic load of the level of a.c. voltage of the electrical network to which the socket is connected. Of course, the term “generic load” is meant to indicate any operating apparatus connected to the socket, whilst the simple connection accompanied by a state of rest of the apparatus itself constitutes, instead, a state of absence of load. The level of voltage of the a.c. network varies, as is known, according to the sphere considered. Domestic networks, for example, are single-phase networks and are characterized by a voltage of 220 V, whereas, for three-phase industrial networks, it is 380 V. In both of the cases referred to, however, each electrical socket is constantly subjected to said values of a.c. voltage even when no load is applied.
The latter condition appears particularly disadvantageous in terms of safety above all in the domestic context, where there are not commonly envisaged particular external protective devices designed to insulate the live contacts of the socket from the surrounding external environment. For this reason, there may occur serious accidents in the case where persons, above all children, accidentally come into contact with the socket. In such a situation, the human body, behaving like an electrical impedance, is traversed by a current intensity which, according to its value, can lead to serious consequences that range from involuntary contraction of muscles, referred to as tetanization, to death due to electrocution. A constant level of voltage applied to an electrical socket has moreover a second negative aspect linked to the onset of electromagnetic emissions in the proximity of the socket itself. It is in fact known how, in the domestic and industrial environments, electrical cables, sockets, electrical equipment, etc. generate electric and magnetic fields in their vicinity. In Italy, for example, said fields have a characteristic frequency of 50 Hz, i.e., that of the supply networks, and an intensity which, instead, varies according to the wiring systems or to the loads applied.
It may be appreciated, then, how electrical sockets, at least ones in current use, present problems of safety and represent a source of undesirable electromagnetic pollution. Even though the effects on man deriving from the exposure to a.c. magnetic fields is not, in fact, yet totally known and controllable, there is by now recognized the need to limit to the maximum this type of emissions obviously where and when this is possible.